This invention relates generally to power management within a computing environment, and more particularly to on-chip voltage regulation.
In many electrical systems, it is desirable to maintain stability of the electrical system regardless of the load impedance applied to the circuitry. For example, sensitive circuitry in a computer system may require a voltage level having high direct current (DC) accuracy and low alternating current (AC) noise for good operation. However, if the circuitry comprises a variable load, the changes in the load may cause an electrical system to become unstable. An on-chip voltage regulator connected between the circuitry and an external power supply (or reference voltage) may be used to create the desired voltage level on the chip local to the circuitry based on the reference voltage. The output of the voltage regulator associated with an electrical system, therefore, should be able to remain stable even when the impedance of the load attached to the voltage regulator varies over time.
An on-chip voltage regulator may comprise a linear voltage regulator. A linear regulator may include a gain path, or loop, with an output of an error amplifier connected to a gate of an output device that acts like a variable resistor. However, a linear regulator may have a slow response to changes in the output loading, since the feedback voltage may have to go all the way back through the error amplifier to affect the gate voltage of the output device.